Plumbing for my sump NEED HELP

I have a custom made sump and will be using a sump for the first time. I have a 75gallon NON drilled reef tank. My overflow box is Eshopps 1200 with 2 overflow hoses. My sump is a 20L with 3 chambers. After reading a few post this is the design i went with. From left to right. Refugium,bubble trap, Return pump, bubble trap, Protein skimmer. I will have water entering at both the Refugium and protein skimmer sections.

My main issue is trying to figure out where should i put my UV Sterilizer. And the reason why i put the Refug first before entering the protein skimmer is because i read you want to have unskimmer water in you refug. I believe this should be the same for the UV.... Is this true.

 

the fuge should be a low flow area hence why you should have it on the other end separate from the skimmer which should have as much flow going through as possible so it skims a good amount of the water also the detritus etc isnt bad for the fuge because itll feed the inhabatants etc and the uv sterilizer should be either in the skimmer or return area the reason it shouldnt be in the fuge is that the micro organisms that the sterilizer kills are beneficial for the most part in the fuge however i have read mixed reviews on whether or not to even have one

 

Ya i have always heard the mixed reviews but i got a good deal on one so i figured id find out for my self. Thanks for the replay. Another question

If i had a ball valve on the return before the UV will that harm/hurt my return pump. I heard restricting the flow of a pump will beat up the pump

 

if it is a centrifugal pump which it probably is it shouldnt harm the pump at all, it will actually make it run more efficient because since there is a higher pressure in the housing it will prevent cavitation(when air gets trapped around the shaft of the impeller) and the cavitation could lead to overheating due to lack of heat exchange through the watter so it'll actually more than likely prolong the life of the pump better and if im correct it will use less power consumption as well and regardless if it did have any affect on anything it would only be the impeller which is +/- $6 to replace, the other components of the pump such as the magnets etc would be unaffected so if you run at a better power efficiency which means less of an electric bill then the $6 every so often isnt a whole big deal